Synthetic or artificial turf is used for a variety of different applications. Since the mid-nineties, long-pile artificial turf (also referred to as third generation or 3G) surfaces have been used for contact sports, such as American Football, Soccer, Lacrosse etc. The evolution of the term 3G refers to long tufted fibers that are tufted into a primary backing medium and then coated with a material such as Polyurethane (PU) or latex in order to secure the fibers in place. The long fibers are then supported/interspersed by an infill medium(s), which provide a balance of product stability and cushioning.
The most common infill medium for stability is graded sand, while the most common material for cushioning or performance is granulated styrene-butadiene rubber (SBR) or the material used for manufacturing car tires. However, other materials can be used, such as Thermoplastic Elastomers (TPE's) and Ethylene Propylene Diene Monomers (EPDM's). The infill material can also include cork and organic infill. The infill material can be used in isolation or combined together either in distinct layers or by mixing together. The typical sand/rubber infill material of an elite level turf system can represent around 900,000 lbs. of material, which is greater than 90% of the overall turf system weight. The infill material may also have a monetary value, which depends on the material type, quality, quantity etc.
Over the lifetime of the field (which can typically be anywhere between 8-15 years), the infill is subject to a very harsh environment, such as ultraviolet light, rain, mechanical wear, extreme temperatures, etc., which can cause the materials to breakdown into finer particles. It is also known that the infill can become contaminated by broken fiber fragments or shards, as well as from detritus, such as rotting leaves, dust, stones, etc.
High levels of fine particles can lead to poor drainage of the turf, whilst foreign material within the infill material, such as stones and metals, can pose a safety risk. Further, broken fiber and other foreign material is unsightly and can detract from the overall appearance of the field.
When recycling or replacing infill material that has reached the end of its life cycle, it would be efficient and environmentally beneficial if the infill material could be recycled or reused. In addition to saving on the cost of purchasing and shipping in new infill, the ‘old’ infill would also be diverted from a landfill.